Semiconductor packaging technology is commonly characterized by the use of a substrate whose front side is mounted with a semiconductor die and whose back side is mounted with a grid array of solder balls. During assembly, wire bonding techniques are used to connect the die with electrical connections on the substrate.
FIG. 1(a) illustrates one commonly employed substrate configuration used in conventional packaging approaches. The depiction of FIG. 1(a) is schematic in nature and not necessarily to scale. The depicted package 100 includes a substrate 102 having a semiconductor die 101 mounted thereon. A variety of methods of mounting such dies are well known in the art.
The schematically depicted die 101 is shown including a few exemplar active components 110 schematically illustrated to show tat the active components 110 can be located inside the die 101. The reader is specifically reminded that this drawing is not necessarily to scale. Conventionally, such active components 110 are located just under a surface of the die. Typically, a multiplicity of bond pads 103 are formed on atop surface 101T of the die 101. Heretofore, these bond pads 103 have been formed only on the outer portions of the die 101. These bond pads 103 are electrically connected with substrate mounted electrical contacts 104 by means of wire bonds 105. Before now, the bond pads 103 have been arranged about the periphery of the die 101 to avoid being placed over the active components 110.
FIG. 1(b) is a schematic top down view of the conventional package 100 depicted in FIG. 1(a). The active circuit components 110 are commonly arranged in an inner portion 120 (the outer border of which is illustrated here by dotted/dashed line) of the die 101. The bond pads 103 are arranged at the outer periphery 130 of the die 101. This arrangement of bond pads 103 at the periphery 130 was previously necessary due to certain limitations in wire bonding technique. Wire bonding to bond pads above an active component frequently lead to failure of the underlying component. As a result, it is common practice to confine bond pads to the outer periphery of the die. Although advantageous from some standpoints, such a limitation commonly places a large majority of the die surface area off-limits to wire bonding. Thus, conventionally, the bond pads 103 are relegated to the outer periphery 130 of the die 101. In conventional approaches, more than one row of bond pads 103 can be used. In fact, in one conventional implementation, three rows of bond pads are used. In one common conventional implementation, using a die of about 8 millimeters (mm) square, the bond pads are confined to an outer periphery of 500 microns (μ) or less. Correspondingly, the entire inner portion 120 encircled by the pads 103 is not used to form bond pads suitable for wire bonding.
Current advances in wire bonding technologies have reduced the likelihood that active components located under bond pads will be damaged by the wire bonding process. The principles of the present invention seek to take advantage of this development. Thus, methodologies and apparatus constructed in accordance with the principles of the invention can be used to form novel packaging structures, some of which are detailed hereinbelow.